Cardiac resynchronization therapy (CRT) can increase quality of life by improving cardiac performance. Most CRTs rely on a set of parameters that can be optimized according to various criteria. As cardiac conditions change, for better or worse, such parameters may be periodically re-optimized. In general, benefits of CRT increase with frequency of optimization. However, certain cardiac conditions can confound optimization or otherwise make optimization problematic. For example, conditions such as bundle branch block (BBB), atrio-ventricular nodal block (AVN block) and atrial fibrillation (AF) often occur in conjunction with congestive heart failure (CHF) and can confound measurement of some intervals used in the QuickOpt™ optimization algorithm (St. Jude Medical, Inc., Sylmar, Calif.). Consider AVN block due to disease or surgically performed AVN ablation; such a patient is often considered pacing dependent due to the lack of proper conduction from the atria to the ventricles. Thus, the condition of AVN block confounds an optimization algorithm for CRT or other pacing therapy that relies an intrinsic atrio-ventricular interval for the right ventricle (RV) or the left ventricle (LV). Consequently, a need exists for techniques to, for example, measure one or more intervals in the presence of AVN block as well as other cardiac conditions. Various exemplary techniques described herein address this need and/or other needs.